Automatic retaining-valve for air-brake systems.



E. U MACK. Y v AUTOMATIC RUNNING vALvEHFoR Am BRAKE SYSTEMSL APPucATmNman FEB. 16.1645. 1911,712. Patented Nov. 23, 1915.`

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AUTOMATIC RETAINING VALVE FOR.AIR BRAKE SYSTEMS.

l APPLICATION FILED FEB. vI6, 1915. 1,151,712.

WIr/158353 l Patented Nov. 23, 1915.

Anon/vm i of Florence, in the county of Florence and' ERNEST U. MACKMQFFLORE-NCEpSOUTH CAROLINA.

AUTOMATICiItETAINING-VALVE FOR AIR-BRAKE SYSTEMS.

Specifica-tion of Letters Patent.

Patented Nov. 23, %15.

Application filed February 16, 1915.' 'Serial-Ne. 6,4%.

To @ZZ 107mm 'it may concer/n:

Be it known'r that l, Enixns'r U.' Miroir,

citizen of the United States, and a'resident State of South Carolina,have invented cer tain new and useful improvements in AutomaticRetaining-Valves for Air-Brake Systems, otwhich the following is aspecifica- The object of my invention is to provide a safety device inan air-brake system which will automatically close the exhaust outletfrom the triple-valve when a full application of the brakes has beenmade andthe air pressures equalize 'in the auxiliary reservoir and brakecylinder under each car of a train', and thus retain the pressure inAthe brake cylinder while the auxiliary resern lconstruction which willnot easily get outvoir is' being re-charged with air from the' mainreservoir on the locomotive.

As is well known, when the pressures equalize in the auxiliary reservoirand brake cylinder, while-the train is moving down grade, it isimpossible to re-charge the auxiliary reservoirs with air or make anyfurther application ofthe brakesvwithout first releasing the brakes,which is extremely dangerous on account of the liability of the train torun away while auxiliary reservoirs are being re-charged, unless thepresent -type ofretaining valves have' already been set on each car byhand before starting the down grade, and these retaining valves must allbe again restored by hand at the foot of the grade on eac-h car. A Y

My invention-provides a device of simple of order toI require repair andwhich will automatically operate for safety when the danger point isreached.

`Mvinvention will also save much time in turning on and off the handoperated retaining valves now in use, and will eliminate the danger tothe lives of trainmen in passing over tops of freight trains coveredwith snow, sleet, and ice.

My invention also permits greater speed of train because of full brakecylinder and auxiliary reservoir pressures available.

My invention is fully described in the following specification, of whichthe accompanying drawings formapart, in which like reference charactersrefer to like parts in each of the views, and in which Figure 1 is alongitudinal section taken through one'forin of my invention, inoperative connection with the auxiliary reservoir, brake cylinder, andtriple-valve, intended to be installedbeneath each car of a train, withI the parte in one position; F ig. 2 is a similar view with the partsinalternate positions; F ig. 3 1s a section taken on the line 3 3 ofthrough a modified form of my invention.

In the drawings forming a part oi`tliis application I have shown twoforms of construction of ymy device, the form shown in Figs. 1 to 3,inclusivekcomprising a casing 5 having three chambers 6,7 and ,the irstof which is divided into two com artments ments beingdesignated 6b and6", the first of whch isin constant communication with the auxiliary.reservoir 9 by means of a pipe 9a, and the latter of which is inconstant communication with the bra-ke cylinder 10 by means of a pipe10a. l

. The compartment A6 is adapted to be placed in communication with thechamber' 7 through a port 7a controlled by a valve 1l carried by a rod12 secured to the diaphragm 6a and having a supplemental valve 13st Figl; and Fig, Il vis a sectional view y ,by means of adiaphragm 6a.. thecompart4\ the opposite end thereof controllin', g a port 7b adapted toconnect the chamber 7 with the outer air; the valve 11 is normallyclosed against a spring 14 the tension of which is ,adjustable'by meansof an adjustable plate 15, and inthisnormal position ofthe valve 11 thevalve 13 is open, as shown in F ig. 1.

The chamber 8 is in constant communication with the chamber 7 by meansof a port 8a and said chamber is divided into two compartments by. meansof a piston 16`having a cone valve 16@L thereon adapted to beV seatediii a port 8b leading to a pipel? in constant communication with theexhaust port 18 of a triple-valve 19, and provided with a safetyvalve-20, the compartments of the chamber S being designated 8c and 8d,and the compartment 8d of.the 'chamber 8 is adapted to communicatedirectly with the atmosphere through a port 8".

When air pressure is pumped up'in theA auxiliary reservoir 9 thepressure increases in the compartment '0b of the chamber '3 through. thepipe 9a; for purposes oflexplanation let us assume that the diaphragm 6ahas an area of two square inches, the valve 11 an area of seven-tenthsof a square inch,

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and the spring 14: a pressureof thirty-eight 1w pounds; as soon as apressure exceeding nineteen pounds per square inch is attained in thecompartment 6b, the spring lil-is overf come and valve 111s forced toits seat Where it is held by the pressure in the compartav When a fullapplication of the brakes is l' made and the air pressures in theauxiliary reservoir and the brake cylinder equal- 103 lbs.) overcomeize, the air passes through the pipe 102L to thecompartment 6, and thecombined forces of the spring 14, (38 lbs.) and the pressure of air (50lbs.) in compartment 6 acting upon an effective area one andthree-tenths square inches on diaphragm 6a (2.- equals 13), (or 38 lbs.plus 65 lbs. equals the pressure in the compartment 6b which is onehundred pounds, (50 lbs. 2m), and the valve 11 moves from its seat andopens the port 7a, permittingairl from the brake cylinder andcompartment 6c to pass to the chamber 7, and thence to the compartmentSetthrough the port this air pressure causes the piston 16 to rise andseats the cone 16a in the port 8b, Aand closing oif the previouscommunication of the exhaust port 18 lof the triple-valve With theatmosphere through the compartment 8"l and vent 8e. The engineer may nowmove his brake valve to release iposition and re!- charge the train-lineand all the. auxiliary reservoirs under all the cars, each ltriplevalve.at this time opening the exhaust from the respective brake cylinder;this air,how ever, cannot escapevfrom the brake cylinders ii'or thereason that the respective cone valves 16 are closed as already.explained,

and the brakes are Vthus held applied While the auxiliary reservoirs arebeing re-charged. It will be understood that the saine 'rnqvement thatopens the valve 11 closes the-valve 13 so no air may escape from thechamber 7. As soon as the valve' 11 moves from its seat the pressures'of air in the compartment 6c and chamber 7 are equalized, and thcpressure of air in the compartment 6c vbecomes eifectiveupon the Wholearea of the diaphragm 6a less the area of the stem l2; this pressureincludes the one hundred pounds, resulting from the ft'y pounds beingmultiplied bv the area 2, and the thirtyeight pounds spring pressure, atotal of one hundred and thirty-eight pounds, noiv acting to hold the`valve 11 open and the valve 13 closed. Pressure may noiv be raised'n theauxiliary reservoir `and compartment 6b to seventy pounds per squareinch, or one 'hundred and forty pounds for the two square inches ofarea, andthe diaphragm will again be over-balancedvalve 11 closed, andvalve 13 opened; air from compartment 8c will now escape through theports 8a and- 7b to the atmosphere, and the pis- SH `rod 22, and I showa piston 210i less areav than the piston 23 to supplant the valve`11.When the pressure in the auxiliary reservoirv following claims,

16a, all auxiliary reservoirs may be recharged anywhere short of seventypounds per square inch and further reductions may be made in brake pipepressure to give added pressure in brake cylinders if desired.

In Fig. 4i 1s shown aY modification, overthe form described, which4operates 1n a similar manner with the exception that the valve 21, theequivalentv of the valve 16, is mount-l ed directly upon the rod 22, theequivalent of the rod 12, but the pressures operate in ythe chambers 6band 6 in the manner already Y 4 described; instead of the diaphragm 6 Ishow a piston which serves to move the exceeds that in the brakecylinder the piston 23 moves to the right and opens the valve 21, thusallowing the air from the triplevalvc exhaust port 18 to pass throughthe pipe 17, past the valve 21, and througlr the vent 25. When thepressure in the brake cylinder' equalizes with that in the auxiliaryreservoir the air passes .through the pipe 10 the piston 23 to the left,thus closing the valve 21, andthe air from the brake cylindersvcannot.exhaust through the triplevalves.

`. When the pressures equalize on both sides of the piston 23 the spring1/-1 closes the valve 21 and the air from the brake cylinder, exhaustingthrough the tripple-valve, cannot exhaust past this valve 21; thispressure, fifty pounds, however, acts upon the area of the valve 21 witha pressure of approximately thirty-eight pounds and holds it closed;this needs to be overcome by an excess pressure of about twenty poundsper square inch in the auxiliary reservoir and corresponding side of thepiston 23 before Uhe valve 21 Will again open to permit the escape ofair from the brake 'cylinder to the atmosphere, and the brakes are thusheld applied until theauxiliary reservoir is recharged.l

While I have shown present preferred forms of embodiment of myinvention, I do not limit myself thereto, but may make changesth'ereover, Within the scope of the without departing from the spirit ofmy invention'o sacrificing its advantages. f

and, aided by the spring 14, moves iso' Having thus described myinvention, I claim as nevi7 and desire .to secure by Letters Patent;'-.l y I 1.`In an air brake's'ystm provided With -a brake cylinder, anauxiliary reservoir,v and a triple valve having` a brake cylinder4 2. Inan `air brake- 'sys tem provided with a brake cylinder, anauxiliaryreservoir, and a tri-ple valve-"havirig-a* brakecylinderexhaust;` ther-combination 'of a casing, tWo elements of different--diameters and areas movable therein, a rod connecting said ele-vv ments,an air 'release valve Ion said rod controlling an air. escape port insaidcasing, and a valve controllingthe escape of air from said triplevalve exhaust port, said casing being in operative connection With saidcylinder-and reservoir and said valves' being operablel into and out. ofclosed positions by the movements of saidelements due to variations inairpressures in said cylinder and reservoir.

3. In an air brake system provided With a brake cylinder, an auxiliaryreservoir, and a triple valve having a brake cylinder exhaust port; thecombination of a casing, a

Aconnecting said reservoir and casing diaphragm therein, a valvetherein, connecting said diaphragm and valve, connecting said cylinderwith said casing between said diaphragm and valve,

a pipe outer side of saidl diaphragm, a pipe connecting saidexhaust portwith the outer air through said casing, and a supplemental valve forsaid exhaust pipe operable by the variations in air pressures insaid'cylinder and reservoir pipes.

4. In an air brake system provided with a brake cylinder, an auxiliaryreservoir, and' a triple valve having a brake cylinderl exhaust port;the combination of va casing, a valve therein controlling said` exhaustport, means including elements of different air pressure areas forcontrollingsaid valve, a pipe connecting s aid reservoir With saidcasing on one side'of one element, and a pipe connecting said brakecylinder With said casing between said elements, said casing hav-v ingpassages therein permitting the air from said last named pipe to impingeon said valve to close the same When the pressure in both pipes isequalized.

In testimony whereof I have name to this specification in the tWosubscribing Witnesses.

ERNEST U. MACK.

signed my presence of Witnesses.:

J. W. HICKS, HENRY E. DAVIS.

` copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

, Washington, D. C.

a rod a pipe.

